From 713410951bfe1cd74adce74db5676b8bcdff078e Mon Sep 17 00:00:00 2001
From: Vladislav Bolkhovitin <vst@vlnb.net>
Date: Thu, 25 Feb 2010 13:37:56 +0000
Subject: [PATCH] Minor fixes and cleanups

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@1520 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 iscsi-scst/kernel/conn.c    |  3 +++
 iscsi-scst/kernel/iscsi.c   |  9 +++++++--
 iscsi-scst/kernel/iscsi.h   |  5 +++--
 iscsi-scst/kernel/nthread.c |  7 +++++++
 scst/src/scst_main.c        | 15 ++++++++++-----
 5 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/iscsi-scst/kernel/conn.c b/iscsi-scst/kernel/conn.c
index 8a5eefe26..65e3e6352 100644
--- a/iscsi-scst/kernel/conn.c
+++ b/iscsi-scst/kernel/conn.c
@@ -442,6 +442,7 @@ out:
 	return;
 }
 
+/* Must be called from rd thread only */
 void iscsi_check_tm_data_wait_timeouts(struct iscsi_conn *conn, bool force)
 {
 	struct iscsi_cmnd *cmnd;
@@ -455,6 +456,8 @@ void iscsi_check_tm_data_wait_timeouts(struct iscsi_conn *conn, bool force)
 		"j %ld (TIMEOUT %d, force %d)", j,
 		ISCSI_TM_DATA_WAIT_SCHED_TIMEOUT, force);
 
+	iscsi_extracheck_is_rd_thread(conn);
+
 again:
 	spin_lock_bh(&iscsi_rd_lock);
 	spin_lock(&conn->write_list_lock);
diff --git a/iscsi-scst/kernel/iscsi.c b/iscsi-scst/kernel/iscsi.c
index 68ec27801..15f617dc3 100644
--- a/iscsi-scst/kernel/iscsi.c
+++ b/iscsi-scst/kernel/iscsi.c
@@ -88,8 +88,15 @@ static void req_del_from_write_timeout_list(struct iscsi_cmnd *req)
 		req, conn);
 
 	spin_lock_bh(&conn->write_list_lock);
+
+	/* Recheck, since it can be changed behind us */
+	if (unlikely(!req->on_write_timeout_list))
+		goto out_unlock;
+
 	list_del(&req->write_timeout_list_entry);
 	req->on_write_timeout_list = 0;
+
+out_unlock:
 	spin_unlock_bh(&conn->write_list_lock);
 
 out:
@@ -151,8 +158,6 @@ void iscsi_restart_cmnd(struct iscsi_cmnd *cmnd)
 	EXTRACHECKS_BUG_ON(cmnd->r2t_len_to_receive != 0);
 	EXTRACHECKS_BUG_ON(cmnd->r2t_len_to_send != 0);
 
-	iscsi_extracheck_is_rd_thread(cmnd->conn);
-
 	req_del_from_write_timeout_list(cmnd);
 
 	/*
diff --git a/iscsi-scst/kernel/iscsi.h b/iscsi-scst/kernel/iscsi.h
index 66fcc1c5c..00970cae8 100644
--- a/iscsi-scst/kernel/iscsi.h
+++ b/iscsi-scst/kernel/iscsi.h
@@ -189,6 +189,7 @@ struct iscsi_conn {
 	/* List of data pdus being sent, protected by write_list_lock */
 	struct list_head write_timeout_list;
 
+	/* Protected by write_list_lock */
 	struct timer_list rsp_timer;
 
 	/* All 2 protected by iscsi_wr_lock */
@@ -319,7 +320,7 @@ struct iscsi_cmnd {
 	struct iscsi_conn *conn;
 
 	/*
-	 * Some flags protected by conn->write_list_lock, but all modified only
+	 * Some flags used under conn->write_list_lock, but all modified only
 	 * from single read thread or when there are no references to cmd.
 	 */
 	unsigned int hashed:1;
@@ -378,7 +379,7 @@ struct iscsi_cmnd {
 		struct list_head write_timeout_list_entry;
 	};
 
-	/* Both modified only from single write thread */
+	/* Both protected by conn->write_list_lock */
 	unsigned int on_write_timeout_list:1;
 	unsigned long write_start;
 
diff --git a/iscsi-scst/kernel/nthread.c b/iscsi-scst/kernel/nthread.c
index 6bb9a384e..a00d32248 100644
--- a/iscsi-scst/kernel/nthread.c
+++ b/iscsi-scst/kernel/nthread.c
@@ -1155,8 +1155,15 @@ void req_add_to_write_timeout_list(struct iscsi_cmnd *req)
 
 	spin_lock_bh(&conn->write_list_lock);
 
+	/* Recheck, since it can be changed behind us */
+	if (unlikely(req->on_write_timeout_list)) {
+		spin_unlock_bh(&conn->write_list_lock);
+		goto out;
+	}
+
 	req->on_write_timeout_list = 1;
 	req->write_start = jiffies;
+
 	list_add_tail(&req->write_timeout_list_entry,
 		&conn->write_timeout_list);
 
diff --git a/scst/src/scst_main.c b/scst/src/scst_main.c
index 62aa6e798..e5ad825c9 100644
--- a/scst/src/scst_main.c
+++ b/scst/src/scst_main.c
@@ -449,8 +449,10 @@ struct scst_tgt *scst_register(struct scst_tgt_template *vtt,
 	mutex_unlock(&scst_mutex);
 	scst_resume_activity();
 
-	PRINT_INFO("Target %s (%p) for template %s registered successfully",
-		target_name, tgt, vtt->name);
+	PRINT_INFO("Target %s for template %s registered successfully",
+		tgt->tgt_name, vtt->name);
+
+	TRACE_DBG("tgt %p", tgt);
 
 out:
 	TRACE_EXIT();
@@ -484,7 +486,8 @@ out_free_tgt_err:
 
 out_err:
 	PRINT_ERROR("Failed to register target %s for template %s (error %d)",
-		target_name, vtt->name, rc);
+		(tgt->tgt_name != NULL) ? tgt->tgt_name : target_name,
+		vtt->name, rc);
 	goto out;
 }
 EXPORT_SYMBOL(scst_register);
@@ -553,10 +556,12 @@ again:
 
 	del_timer_sync(&tgt->retry_timer);
 
+	PRINT_INFO("Target %s for template %s unregistered successfully",
+		tgt->tgt_name, vtt->name);
+
 	scst_tgt_sysfs_put(tgt); /* must not be called under scst_mutex */
 
-	PRINT_INFO("Target %p for template %s unregistered successfully",
-		tgt, vtt->name);
+	TRACE_DBG("Unregistering tgt %p finished", tgt);
 
 	TRACE_EXIT();
 	return;